The primary objective of this proposal is to evaluate the efficacy of vitamin supplementation (beta-carotene, vitamin C, and vitamin E) in the treatment of oral mucosal lesions. Specifically, we plan to recruit 200 patients with oral mucosal lesions over a three year period. The following data will be obtained: diagnostic biopsy, measurement of the lesion size, clinical photographs, serum and tissue samples to determine vitamin levels, exposure to risk factors, and diet history. Clinical and biochemical evaluations will occur 1, 3, 6, and 9 months after initiation of supplementation. This will permit a statistical comparison of changes in the oral lesions to vitamin levels in the blood and tissue, exposure to risk factors, and diet. Based on the sample size, the estimated power of the repeated measures ANOVA to detect a difference among the four groups is 81% and is 86% for multinomial logistic analysis. The significance of this double-blind randomized clinical trial is that it will determine if vitamin supplementation at this dosage can reduce the size or oral mucosal lesions.